The present invention relates to an oil separator that separates suspended oil from a gaseous medium. More specifically, the invention relates to an oil separator that achieves oil separation via an increasing centrifugal force.
In compressors typically used in refrigeration and air conditioning systems, such as swashplate type compressors, a mist containing lubricating oil suspended in the gaseous refrigerant medium is often discharged from the compressor. That is, the high pressure refrigerant expelled by operation of the compressor frequently comprises a mist containing droplets of oil used to lubricate the moving parts of the compressor. Due to differences in various physical properties between the oil and the refrigerant, any oil that remains suspended in the refrigerant as it travels throughout the refrigeration circuit can reduce the performance of the compressor and refrigeration system. For example, by reducing oil available to the moving parts of the compressor, the compressor is susceptible to increased wear and seizure potential. Also, oil deposits on heat exchangers can reduce their efficiency.
To combat these problems, an oil separator can be added to the refrigeration circuit, and is typically positioned between the compressor outlet and condenser inlet. The oil separator functions to separate the suspended oil from the gaseous refrigerant. Several designs have been proposed for such oil separators. For example, U.S. Pat. No. 5,159,820 to Ohishi et al. for an xe2x80x9cOIL SEPARATOR INTEGRALLY MOUNTED ON COMPRESSORxe2x80x9d, hereby incorporated by reference in its entirety, discloses an oil separator that utilizes centrifugal force on the mixture to separate the oil from the refrigerant. The oil separator of the ""820 patent comprises a body for forming an oil separating chamber and an oil storage chamber. A separating plate divides the two chambers and an inlet passage is tangentially connected to the oil separating chamber and travels toward the separating plate. A medium outlet passage extends inwardly into the oil separating chamber, and an oil outlet passage is provided in the separating plate.
Considering the potential effects of oil being gradually removed from the compressor due to its suspension in the refrigerant output, there is a need to improve the state of the oil compressor art.
The present invention provides an oil separator that comprises a cylindrical portion, a tangentially connected inlet passage, a refrigerant outlet passage having an inner opening optimally positioned within the interior of the oil separator, a lower portion, and an oil outlet. The lower portion provides a cross-sectional diameter that decreases as the lower portion proceeds from top to bottom. Also, the present invention provides a swashplate type compressor that includes such an oil separator.